Comparing Liposomal Bupivacaine to Bupivacaine Interscalene Blocks for Arthroscopic Rotator Cuff Repair Surgery: A Randomized Controlled Trial

All patients will receive preoperative oral multimodal medications consisting of acetaminophen 975 mg, gabapentin 300 mg, and Celebrex 400 mg.

After completion of the preoperative process the patient will be placed in the supine position with the head of the bed elevated 30 degrees with standard ASA monitors applied. Sedation will be provided with midazolam 0-2 mg and propofol 50 mg. The interscalene groove will be identified with the ultrasound. Using sterile technique, a 21g Nerve block needle will then be inserted and advanced under ultrasound guidance until it is in the interscalene groove. Once in the interscalene, 20 mL of local anesthetic will be injected, with 10 mL deposited at the top of the brachial plexus and 10 mL at the bottom. In the study group, 5 mL of each 0.5% bupivacaine and LB will be injected at each location. The control group with have 20 mL of 0.5% bupivacaine divided between the injection sites. The patient will be monitored in the preoperative area until he/she is brought into the operating room for their procedure. A working block prior to surgery will be confirmed via sensory testing of the shoulder.

All patients will undergo a standard induction with propofol 1.5-3.0 mg/kg, ondansetron 4 mg, dexamethasone 10 mg and ketamine 0.25 mg/kg. A MAC or general with LMA or ETT will be placed and an opioid sparing technique will occur. Standardized maintenance will be a propofol infusion without neuromuscular blockers. 25-50 mcg of IV Fentanyl will be utilized for increases in heart rate greater than 20% or increases in systolic blood pressure above baseline.

Once in the operating room the surgeon will use 10 mL of 0.25% bupivacaine for skin, subcutaneous, and intraarticular injection.

When the operation is complete, the patient will be woken up and brought to the PACU. There the patient will receive IV fentanyl for a pain score of greater than 7. If more than 100 mcg of fentanyl is given and pain still remains above a 7 then IV hydromorphone will be used. A dose of 5-10 mg of oral oxycodone (or 2-4 mg of oral hydromorphone) will be given as soon as the patient is able to tolerate oral medication per standard protocol: If their pain score is 4-6 (on the Visual Analog Scale) then 5mg oral oxycodone (2 mg hydromorphone) can be administered, if their pain is between 7 to 10 then 10 mg of oxycodone (or 4 mg of hydromorphone) can be administered. Once the patient meets discharge criteria, they will be discharged home where each day they will fill out a pain diary. Additionally, a member of the research team will call the patient for signs of complications and ask the patient their current pain score, total opioid pills taken and non-opioid pain medication taken at 24, 48, and 72 hours postoperatively. Additionally, they will perform a Quality of Recovery Score survey at 72 hours, and 14 days postoperatively. An Ultrasound of the diaphragm will be completed by a blinded anesthesiologist in the PACU to assess diaphragm function.